Ion channels make up one of the largest classes of therapeutic targets in the pharmaceutical and biotechnology industry, especially in the areas of cardiac, pulmonary, and gastrointestinal health. The therapeutic targeting of proteins involved in regulating the flux of ions into and out of a cell have dramatic effects on patient health. Testing compounds for their ability to modulate ion channel targets can be difficult and time consuming. The patch-clamp assay is an extremely sensitive assay for the biological action of ion channel modulators. The patch-clamp method, however, is complicated and has a low throughput of test compounds.
Other methods of assaying ion channel activity require recombinant expression of the ion channel or portions of the ion channel in a cell and/or the use of fluorescent or radioactive labels. These approaches, while useful, limit access to drugs that target only a small portion of the channel functions. Furthermore, the recombinant ion channels may not function as they do in a native cell.
The methods of the current invention allow efficient high through put, label-free screening of parental (non-recombinant) cell lines without manipulation of the cells for specific response to test compounds that may be useful as drugs.